Circuit breaker



Jung 15, 1943. o. JENSEN CIRCUIT BREAKER 5 sheets-Sheet 1 Filed April 27, 1940 INVENTOR. OTTO JEN SEN ATTORNEY.

June 15, 1943. o. JENSEN CIRCUIT BREAKER Filed April 27, 1940 5 SheebS--Sheeil 2 INVENTOR. o-r'ro JENSEN, BY i v g ATTORNEY,

o. JENSEN CIRCUIT BREAKER Filed April 27, 1940 5 Sheets-Sheet 3 June 15, 1943.

June 15, 1943. o. JENSEN CIRCUIT BREAKER Filed April 27, 1940 5 Sheets-Sheet 4 www, w

INVENTOR. OTTO IEN SEN BY i Z ATTORNEY.

June 15,1943. Q JENSEN 2,321,603

CIRCUIT'BREAKER Filed fApril -27, 1940 5 sheets-sheet 5 v lmlulllll 271 "1 ml f INVENTOR. o T'ro JE NsEN BY Z' I ATTORNEY.

Patented June l5, 1943 CIRCUIT BBEAKER Otto Jensen, Glenside, Pa., assigner to I.T.E.

Circuit Breaker Company,

Philadelphia, Pa., a

corporation of Pennsylvania Application Aprii'z'z, 1.94'o, semrNo. 331,9.67 s claims.' (ci: zoo-ss) This invention relates to switch gear and circuit breakers, and'more particularly to a' panel type ycombination switch and circuit breaker adapted for use in branch circuits of various types and arranged'to be mounted upon a panel board together with other similar devices for controlling a plurality of circuits.

In the operation of branch circuits, it is frequently important to connect or disconnect in'- dividual circuits from the main line Without interfering with the operation of other similar circuits, and to 'arrange for overload protection for individual circuits so that in the event of any fault inf any particular branch, that particular circuit may' automatically be disconnected without interfering in any way with the operation of other-'circuits or with the operation of the main circuit itself. i.

Thus, in the operation motorsor various v of a plurality of small purposes in a shop, it is important that any fault occurring'in' the circuit,

to a particular motor should not affect the operation of other motors or the-main line to 'the 'end that continuous operation should' as far as pos,- sible be maintained.

Likewise, in the operation of multiple dwell-- ings or apartment houses where a plurality of individual circuits for different apartments are all connected to a single main line, it is important that any particular circuit to any particular' apartment be readily connectible to and disconnectible from the main line and that any iault in any particular circuit should not disturb the operation of any ot the other circuits.

Accordingly, the purpose and object ci the present invention is to provide a simple combination on-o switch and circuit breaker which be mounted upon a panel board and connected between the main busand the individual branch circuits in order to provide suitable manual or automatic control for each of the individual circuits.

In order to provide for panel board mounting of this type and in order further to provide for simplicity in operation and assembly and to facilitate mounting upon the panel board, it is lmportant that the particular combination switch and circuit breaker be compact and nevertheless so arranged as to obviate any internal faults or short circuits.

Therefore, instead of providing for the creation of a simple air-gap between the movable contact member and the stationarycontact member of .switch circuit breaker combination, important objects of the present inthe on-oit one of the to provide for .ner that upon of dielectric material the biasing means will iminafter referred to vention is to provide for the interposition of an Still another extremely important object ofY the present invention is to so arrange the sta- 'tionary and movable contacts that they are separated not by any operation initially -performed upon the movable contact itself, but by the sweeping or swinging of the physical barrier ofv dielectric material toward circuit opening position. In such case, the barrier may swing beneath, bearing on the movable contact arm, raising the arm, and separating the contacts, and then the barrier by'continuing the movement reaches its nal position between the separated contacts.

The movable contact should therefore be so arranged that it is biased into contacting position with the stationary contact in such manrcmoval of the physical barrier mediately reestablish contact pressure between the movable and stationary contacts. l

Still another object of the present invention is individual and separate physical barriers for each of the two operations of ordinary manual switching' and automatic switching. That is, one barrier of dielectric materiai herea as an interposer may be placed betweentbe contacts by manual operation and another such interposer may be interposed betwe., the movable and stationary contacts by automatic circuit breaking means. Both of these barriers may operate in a single plane and it is still another object of the present invention to utilize the manualiy operated interposer or oarrier to remove the automatically operated inter between the contacts when The circuits and apparatus may be designed to carry (a) a maximum current above and below which small variation may occur (b) a heavy` ceeds the normal maximum value, thenv however,

the circuit should be possible.

interrupted as quickly as It is an important object o! the present invention to provide for independent means for automatically operating the circuit breakerI in accordance with either of these conditions.

In the case of a short circuit where the resistance drops to zero or substantially zero, this invention provides for an instantaneous trip mechanism for immediately separating the contacts. Where a fault occurs however vwhich is not suiiicient to cause operation ofthe instantaneous trip mechanism but is nevertheless such that excess heat may be generated in the circuit, then a thermal means responsive to increased heat in the circuit may be utilized for the purpose of automatically'separating the contactsvin accordance with the aforementioned 12T characteristic.

A further important object of the present invention is to mount the interposter which is automatically brought between the contacts by either of the means abovementioned in such a manner that it is always biased toward contact separating position so that in the event of failure of the mechanism, the automatically operated interposer would be more likely to moveto a position separating the contacts than to any other position.

A further object of this invention includes the mounting of the manually operated switch lever in such manner that it is yieldingly but positively held in the open circuit or closed circuit position.

Still another object of this invention is to so arrange the insulating housing of the circuit Y breaker that it may be readily molded by means of ordinary core dies without any other expensive molding or forming processes.

Still another and extremely important object of the present invention is the arrangement of the housing of the combination switch and circuit breaker, and the various parts thereof in such manner as readily to facilitate assembly. That is, the housing is so formed and each of the parts is so formed that the parts may readily successively be placed in the housing from one side, the assembly operation requiring merely a series of successive steps without any requirement for complicated tools or complicated supporting and holding meansfor combining and supporting .the members during assembly.

A still further object of the present invention is to s o arrange the housing and each of the parts that when the cover plate is secured to the housing at one side thereof, each of the parts is securely locked in operative position.

. showing the automatically operated-interposer in Many other objects and uses of the present invention will Ain part be apparent and in part pointed out in the following description and drawings, in which:

Figure 1 isA an external view of the combination switch and circuit breaker.

Figure 2 is an elevational view showing a plurality of the members oi' Figure 1 mounted upon a panel board.

Figure 3 is a. cross-sectional view takenon line 3-3 of Figure 2L Figure 4 is a side view of the circuit breaker of Figure 1 with the cover plate ,removed and with the contacts and various members arranged in open circuit position.

Figure 5 corresponds to the view of Figure 4 showing the contacts and various members in ordinary closed circuit position.

Figure 6 is a cross sectional view taken on line 6-6 of Figure 4, looking in the direction of arrows.

Figure 'I is a cross-sectional View taken 0n line the -line I3--I3 of Figure 8.

tripped position. A

Figure 10 is a cross-'sectional view line lil-,I0 of Figure 4.

Figure 11 is a cross-sectional view line II-II of Figure 10.

Figure l2 is` a cross-sectional view line i2'-I2 of Figure 4.

Figure 13 is a cross-sectionaiview taken on taken on taken on taken on Figure 14 is a cross-sectional View taken line M-H of Figure 11.

Figure 15 is an explodedview of the combination switch and circuit breaker showing the manually operated interposer in circuit breaking position.

Figure 16 is an exploded view of the combination switch and circuit breaker showing the automatically operated interposer in circuit breaking position.

Referring now to Figure 1, I have here shown my combination switch and circuit breaker which comprisesv a principal housing 20 and a cover plate 2l secured thereto in any suitable manner, as for instance, by means of rivets 22.

The combination' switch and circuit breaker comprises a manual operating handle 23and circuit connecting means, separable contacts and automatic tripping means hereinafter more particularly described.

The combination switch and circuit breaker of Figure 1 is of a form and construction peculiarly adapting it for panel boardy operation for controlling a series of branch orsubsidiary circuits fed from a main line or bus. The arrangement of the members of` Figure 1 upon the panel board as well as the arrangement of the various external portions of the switch and circuit breaker combination adapting it for use in panel boards will be more readily understood from a description of the interior construction and relationship of the parts of the circuit breaker itself.

The member of Figure 1 is shown in ordinary closed circuit position which, when the cover plate is removed, corresponds to the arrange-" the combination switch and circuit breaker com- 4prises a terminal or circuit connecting member 3N having any suitable means such as the threaded perforation 3| therein for connecting the circuit breaker to one termina-l of the circuit. The current is led to the connecting lug 30, which is preferably connected to the load from the integrally associated conductive bar `32 which is connected, through the projecting lug 33 of the bar l32, to thebi-metallic element 34.

The bi-metallic thermal element is at the bottom thereof connected to the exible wire connection; preferably a copper braid 35 which is in turn conductively connected to the solenoid coil 31. The solenoid coil v3'I, is connected by means of the integral connecting bar 38 to the movable contact-carrying bar 39, the said contactcarrying bar being preferably an integral extension of the bar 38.

yent invention relies not on a insure a firm grip,

39, as will be seen The contact-carrying bar preferably in connection with Figure 13, carries the main movable contact block 4I. The current enters the contact block 4I at the movable contact surface 4| from the stationary contact surface 42 when the switch is closed. tact surface 42 is carried by the stationary contact supporting bar 43 (see Figures 13 and 16) which is in turn connected by the angular lead-in bar 44 (Figures 4 and 16) to the opposite terminal or lead 45 into which the current l It will thus be seen that when the circuit breaker is so arranged that one terminal 30 thereof is connected through the load to one pole of the circuit and the opposite terminal 45 (connected to the stationary contact) is connected to the opposite pole of the circuit, then the current;l path is through the two contact surfaces 4| and 42, and

is led from the bus bar.-

that any breaking of these. contacts, that is,4 any separation thereof, will the circuit. Such separation of the contacts may be accomplished either manually, whenever it may be desired, or automatically in response to faults or over current conditions occurring in the circuit which the present circuit breaker is designed to protect.

For the purpose of separating contact surfaces and 42 it may be sulilcient merely to move the movable contact a sufficient distance away from a stationary contact so that the air or gases between them furnishes sufiicient dielectric interposition to prevent effectively the passage of current therebetween.

Where, owing to the fact that for panel board mounting of these circuit breakers, the various di-I 5 mensions thereof must be compressed as far as possible and the amount of travel permissible in the movable contacts is relatively limited. then in order to effectively brealr the contacts apart so that no current may flow therebetween, the pressumcient movement of the movable contact to accomplish this purpose, but principally on the interposition of a physical barrier of dielectric material which either effectively serves to lengthen any possible arcing path beyond the limits within which an arc may be maintained for the particular current and voltage rating of the circuit breaker or effectively serves to prevent any arcing path whatever.

iecordingiy, for manually separating the ccntact when it is desired at selected` tervals to disconnect the particular branch s.; uit controlled by the switch and circuit breaker comcinaticn, l prefer to utilize the manually operated interposer il@ (see particularly Figures d, 5 and l5).

The manually operated interposed 5G is so arranged as seen in Figures v5 and a,

be readily moved from the position shown in Figure 5 to the position shown in Figure Al, where it is interposed beteween the contacts as is even more particularly seen in Figure i2.

The manually operated interposer 5l) is connected by rivets 5|, 5| or in any other vsuitable manner to the foot 52 of the manual operating lever 23. The manual operating lever as is more particularly seen in Figures 4, 5 and 15, comprises a iinger grasping portion 60, knurled to a foot 52 for supporting the barrier 5D, and a central pivoting portion 6|. Preferably the manual grasping portion 60 and the central pivoting portion 6| as well as the foot 52 are integrally molded from insulating material as a single unit.

The interposer 50 securely attached to the foot 52 preferably is formed and pressed from result in an opening of that it may a suitable insulating dielectric material to a thickness facilitating, interposition lbetween a movable and stationary contact. The central portion 6| of the manual operating arm 23 comprises, as is more `particularly seen in Figures 4, l5 and 16, a central opening or perforation ll into which projects a knife edge 1|, preferably integrally molded with the entire manual handle portion 23. c

Owing to the fact that the handle 23 preferably is maclev of insulating material which may under appropriate circumstances possibly be brittle, the wide base knife edge 1| is given a sufficiently so that in ordinary operation it will be adequately supported for the purposes here? inafter described. The perforation 10 in the manual handle member 23 and the knife edge 1| thereof cooperate to form a relatively frictionless playless bearing for the handle 23 when the perforation 1I thereof is mounted over the supporting post or spindle 12.

The supporting post or spindle 12 preferably is of. insulating material integrally molded as a When the manual operating handle 23 is mounted upon the spindle 12 so that the knife edge 1I thereof registers with the angle 14 of the spindle and so that the perforation 10 of the central portion 6| of the manual operating member cooperates with the vremainder of the spindle 12, then the manual operating handle 23 may readily be. rotated about the spindle. within definite limits or stops. That is, the manual operating handle may be rotated from the p'xsition shown in Figure 5 to the position shown in Figure 4, in each case the side of the knife edge approaching one of the surfaces of the cutout 'i3 ofthe spindle.

During the actual rotation, the principal bearing surface between the manual operating handle and the spindle is the knife edge 'ii oi the manual operating handle pressing into the angle 'M of the spindle. Thus even though the perforation "itl of the manual operating handle is slightly larger in diameter than greatest di ameter of the spindle, nevertheless the pressure of the knife edge Tl of the handle into the angle iii of the spindle furnishes an efficient, playless bearing. n

ri-he bearing herein is described as a playless one simply because it is not a pointto-point contact between a point and an angle but a knife edge contact overan appreciable length with a corresponding angular member; and such a knife edge contact over such appreciable length prevents any wobble or torque of such nature as to twist the handle out of a plane perpendicular to the axis of the spindle.

The finger grasping portion 5!! cf the manual operating handle 23 projects through the slot BJ in the upper surface 8| of the housing. The movement of the The manual operating handle 23 is so arranged :that it is yieldinvgly biased either in open circuit position ,when it is left in that position or 'closedf circuit position. Thatis, a spring 90- `is so arranged relative'to the center of rota.-

tion of the manual operating lever that when the manual operating lever is moved either toward closed or open circuit position, the spring passes beyond center and serves yieldingly to lock the manual operating lever in place.

The compression spring' 90 (Figures 4, 5 and v which accomplishes this function is mounted upon a slidable steel bar 9| which terminates at'y 'I'he spring 90 is maintained under compressionbetween the bearing plate 95 and the flanges of the yoke or bearing end of the steel bar 92. As-may readily be seen in Figure 5, when the manual operating arm 23 is rotated into position where the interposer is n'ot between the contacts and hence when the circuit breaker is in closed into closed .circuit position,` when it is left in p circuit position, then the effective pressure exl erted by the compression spring 90 between the bearing plate 95 and the notch 92 is so directedbeyond the center of rotation of the manual operating lever 23 (the knife edge Il and anglef'M engagement) as to exert a'torque upon the manual operating lever 23 tending to drive it even further in such direction as to swing the interposer 50 away from the contacts and to swing the linger grasping portion 60 thereof up against the stop 83. l Y

When the manual operating lever 23 is rotated from the position shown in Figure 5 to the open circuit position shown in Figure 4 and the interposer 50 is interposed between the contacts v to produce the open circuit position, then as will be noted by a comparison of Figures 4 and 5, the notch 92 of the central portion 6| of the manual operating lever 23 has been rotated to such position that the effective force generated by the compression spring 90 is directed beyond the center of rotation of the manual operating lever in an opposite direction from that in which it was directed in the closed circuit position of Figure 5, thus tending to drive the finger grasping portion 60 of the manual operating arm 23 against the stop 82 and tending furtherto drive interposer 50 into open circuit position.

' Obviously the reason that the -compressive force of the spring 90 is either in the open or in the closed position exerted in s uch direction as to maintain the particular position of the switch (Whether open or closed) is that the axis of the spring is in each case shifted beyond the center of rotation so that the effective direction of the force exerted by the spring changes from a counterclockwise direction with respect to Figure 5 to alclockwise rotation with respect to Figure 4 about the center of rotation.

As will be noted from a comparison of Figures 4 and 5, the spring 90 is in a position under greater compression and much less beyond center when the switch is in the open circuit position of Figure 4 than when the switch is inthe closed 'circuit positionof Figure 5.

Accordingly, a positive closing action is provided 'for the closing of the switch, that is, it requires only a slight movement of the linger grasping portion 60 of the manual operating 1ever 23 (when the circuit breaker is in the position shown in Figure 4) to move the manual operating lever 23 so that the force exerted by the spring 90 passes through center and is exerted in an opposite sense to snap the manual operatingarm 23 into closed circuit position.

Thus, when the switch is in open circuit position, it requires merely flicking of the linger grasping portion 60 of the manual operating lever 23 ,to cause the interposer 50 to be snapped out of its position between the movable and stationary contact. Alsol for this reason, the possibility that the contacts might remain in bare proximity to each other without actual complete removal of the interposer is greatly minimized since in the circuit opening position it is necessary for the circuit opening movement to be substantially completed manually or else the manual operating lever 23 and the finger grasping portion thereof will immediately snap back to circuit closing position.

The position of the linger grasping portion 60 u of the manual operating lever 23 generally will indicate the on or off condition of the switch unless the switch or circuit breaker has 'been automatically tripped open in which case other indicating means hereinafter described may be utilized.

In order that, upon the removal of the barrier 50, from the position shown invFigure 4, where it is between the movable and stationary contact to the position shown in Figure 5 where it is no longer between these contacts, the movable contact should come into closed current conducting `contact with the stationary contact, I provide a leaf spring |00 (Figures 4, 5 and 16) which tends to drive the movable contact surface 4| (see also Figure 13) down upon the stationary contact surface 42. The leaf spring |00 preferably is ,mounted upon a surface |0| of the housing and 'secured thereto by a washer |02 and one of the rivets 22a which serves to secure the cover plate 2| to the housing. In order to insure that the leaf spring will be accurately po- 4| thereof into engagement with the stationaryl sitioned to exert proper contact pressure upon the movable contact, I provide a lug |03 extending from the leaf spring and registerable with a recess |04 of the housing which registry will serve adequately to prevent undue rotation of the leaf spring aroundthe screw 22a.

'I'he leaf spring |00 preferably is formed of any suitable elastic metal preferably of spring steel and is so arranged and bent as seen particularly in the perspective exploded view of Figure 1 6 as to exert pressure upon the contactcarrying arm 39 in such direction as to bias the contact, block 40 and the movable contact surface contact surface 42.

In order further to ensure that the movable contact-carrying arm 39 cannot escape the pressure, I prefer to shear the end ||0 of -the leaf spring |00 in such manner as to provide a pressure transmitting surface thereon which presses down upon the contact bar and to provide guide flanges ||2 and ||3, the edges of which engage the sides of the contact-carrying bar 39, and prevent the escape of the contact-carrying bar from the leaf spring and vice versa.

Obviously a great deal of friction would be generated by the movement of the barrier 50 be-` that may occur during 13) is placed upon the tween the surfaces 4| and 42 of the contacts unless some friction reducing means were provided. Such friction reducing means, however, must be of such a nature as not in any way to interfere with the eifective pressure between the two contacts when the circuit is to be closed, while it must be readily usable to reduce the friction caused by the passage of the interposer 50 during the movement of the interposer 50 between the contacts.

Accordingly, a wheel |20 made of suitable insulating material is loosely mounted'as is more particularly seen in Figures and 13 upon a rivet |2| which is in turn mounted in the perforation |22 of the movable contact block'40.

The stationary contact surface 42 projects somewhat as will be seen inFigure 13, above the main portion of the stationary contact-carrying -bar 43. In order to protect the Bakelite housing from the effects `of any momentary arcing the instant of breaking of the. contacts.v an insulating plate of any suitable material (see inner side of the housing and over the stationary contact supporting members.

The insulating plate |30 has a perforation |3| therein which registers with the stationary contact surface 42. The insulating plate also has a perforation |32 therein which provides a recess into which the wheel |20 maydescend so that Aadequate pressure may be maintained between the contact surfaces 4| and 42. Inorder further to protect the housing 20 at |35 from any arcing that might occur during the instant of opening of the circuit, an additional small plate |35 of insulating material is placed beneath the perforation |32^eil`ectively to protect the housing from any st ray arcs that might momentarily exist.

When the contacts are in closed circuit position, it will thus be noted by reference to Figure i3, that the contact surfaces 4| and 42 may come into close positive abutment in relation to each other owing to the fact that the recess S32 in the base insulating plate |30 permits the wheel |20 to descend beneath the surface of the contact without creating any back pressure tending to separate the contacts or tending to raise' the movable contact away from the stationary contact. Further, since after a period of use, the contacts may wear, the contact supporting members must be capable of movement closer together. The depth of the recess is such as to provide allowance for this additional movement during the life of the breaker. The prime purpose of the wheel is to prevent.frict ion between. the interposer and the contact surface.

When the interposer 50 slides between the contacts it, however, as will clearly be seen by a comparison of Figures 4 and 5 with Figure 12, first comes into contact with the freely rotatable wheel |20. Since the wheel is freely rotatable the barrier may readily slide thereunder and owing to the fact that the barrier is arranged so as to be unyieldlngly mounted in its own plane, then the continued sliding of the interposer 50 owing to manual or other pressure, will cause a raising of the wheel |20 and a consequent raising of the movable contact block 40'fand of the movable contact surface 4|, interposer 50 to slide between the contacts.

In order to facilitate this, fthe interposer 50V thus permitting the" Y However, ordinarily th interposer 50,.

. in resistance, it becomes particularly Figures 8 and lzgrzitral portion |5| and a latch engagingfarm 4c may be bevelled at the leading edge thereof which first comes into contact with the wheel- |20 in' order to facilitate the arising of the wheel.

it is of sufficient thickness to providefor a sumcient dielectric barrier between the contacts when it is in open circuit position and although it is Ioi' sufficient strength to permit it to separate the contacts by the means herein described it is nevertheless suiiicienthf thin so as to not make any suchA bevelling essential for the purpose of lifting the movable contact wheel.

By this means, therefore, the contacts may be manually opened or closed from the outside of the housing by merely applying finger pressure in the proper direction to the finger portion 50 of the manual operating lever 23.

In the event of sudden overloads ofV great intensity or in the event oi' a sudden large drop important immediately and automatically to open the circuit, that is, to separate the movable and stationary contacts. Likewise, also, in the event of an overload of less intensity or a drop in resistance below normal and suilicient to permit the passage of current to such an extent as to cause` over-heating', means are provided in the present device for also separating the movable and ,stationary contacts and thereby opening the circuit at that point.

Both of such means, that is, the means responsive to sudden increased overloads and the means responsive to milder overloads which eventually may be deleterious, are so arranged as to actuate the automatically interposable barrier or interposer |50I (see particularly Figures 8 and 9 as well, as Figures l5, 4,- and 5). The automatically interposable interposer |50 comprises, in addition to thel interposing portion thereof which isf preferably made of substantially the same dielectric material as the interposer 50, a

The central or mounting portion 5| of the automatically interposable interposer |50 is as is most clearly seen in AFigures 6, 8 and 15, perforated at |53 to permitfthe mounting of the interposer |50upon the spindle 12.

The spindle 'l2 has an increased diameter at |54 which is the base portion thereof, most closely adjacent to the wall 4of the housing. The cutout portion 13 of the spindle 12 nevertheless extends into this larger portion of the spindle and the angle 'i4 formed between the surfaces of the cut-out portion .also extends into the enlarged portion of the spindle. The enlargement of the spindle l2 at |54 permits not only for a more secure connection between the spindle and the permitting accurateregistry of the perforation |53 with the large portion of the spindle |54, while the perforation 'I0 of the manual-operating lever 23 is of a size registering with the narrower portion of the spindle 12.

Thus after the automatically interposable member |50 has been placed upon the wider portion of the spindle |54, the manual operating lever may be placed thereon and by reason of the fact that the side thereof abuts against the surface portion |50 of the wider portion |54 of the spindle, the manual operating lever cannot in any way interfere with the operation of the automatically interposable interposer |50. This is more particularly so since the mounting portion |5| of the automatically interposable member |50 although v is slightly narrower than the length of the wider portion |54 of the spindle 12 so that the mounting II may be free of contacty with the central mounting portion 5| ofthe manual Operating lever 23.. V

The interposable barrier |50 is so arranged that it may be readily rotated about the portion |54 of the spindle. For this purpose, an 'angular projection IGI is integrally extended from t e body ofl the mounting section |5| of the int rposable member |50 into the perforation |53. The angular projection '|61 registers with the angle 14 in the spindle and provides a suitable bearing for the rotation of the automatically interposable barrier |50,

Rotation of the vautomatically interposable member |50 about the spindle is also limited by the spacing of the'walls of the spindle which surroundsthe angular portion 14 thereof. `That is, as seen in Figures 8 and 9, a positive stop is provided in each directionof movement of the interposer |50 by the abutment of the sides of the angular portion |5|against the walls of the spindle which join to form the angle 14 thereof.

A compression spring |10 (Figure 8) is mounted on a steel slide bar 1|. 'I'he steel slide bar has a yoke or bearing surface |12 which at one end thereof bears against'a notch |13 of the automatically interposable interposer |50. At the opposite end of'the slide bar, the bar is at |14 inserted in a perforation |15 of an insulating bearing plate |16. The end |14 may slide freely in the perforation'|15.

Compression spring |10,is under compression between the bearing plate |16 and the flanges of the end bearing |12 of the steel slide bar |1|. As may be noted especiallyvin connection with`Figure 8, even when the automatically interposlable barrier |50 is not between the contacts, theaxis of the compression spring |10 is so arranged that,

the force exerted thereon isbelow the center of rotation at |6| and hence is `so directed as to cause the interposer |50 to rotate in a counterclockwise direction with respect to Figure 8.

The interposer |50 is restrained from counterclockwise vmovement in response to the action of compression spring |10 by the latch Aengaging arm |52 thereof. The latch engaging arm |52 carries secured thereto by rivets or any other suitable fastening means, a steel bearing plate |80 which engages the latch |8| of the trigger |82. Upon movement of the trigger |82 in such a direction as to release the engagement between the metal bearing |80'and the latch |8| there is no further restraint upon the rotation of the barrier |50 and since the action of the compression spring |10 is such as to immediately initiate counterclockwise movement thereof with respect to Figure 8, then immediately upon such disengagement, the compression spring |10 `will force theinterposer |50 into the position shown in Figure 9 where it extends between the movable and stationary contacts.

The open circuit position of the barrier |50 is definitely fixed by the abutment thereof against the edge of the handle shutter l5|II which thus halts continued rotation of the interposer |50 in response to the action of the spring |10.

By proper arrangement and spacing of the shutters (that is thev closed circuit non-interposing position of the shutter 50 and the open cir-l cuit interposing position of shutter |50), it is possible to ensure that in the tripped position of the circuit breaker, the interposer |50 will be positioned as shown in Figure 9 directly between the movable and stationary contacts.

The abutment of the edges of the shutters in the tripped position forms a.complete continuous seal between the contacts cutting on any possible effective v,arc path. Thus it may be seen by a comparison of Figures 8 and 9 with Figures 4 and 5, that when the manually operated interit may readily move from the position' shown in Figure 8 to the position shown in Figure 9 immediately upon release of the latch |8| of the trigger |82 from its'engagement with the metallic bearing surface |80 of the latch engaging-- portion |52 of the interposer |50.

Therefore when by the .operation of the man4 ual operating lever 23, the barrier 5' is moved to closed circuit position, that is, to a position where it no longer extends between the movable i contact and the stationary contact, no impediment of any kind exists to the automatic inter-- position of the interposer |50 beween these con. tacts in response to a release of the latch engaging portion thereof |50 by the trigger |82.

Normally when no fault conditions exist upon a line, the trigger |82 is so arranged that the latch portion |8| thereof engages the bearing |88 ofthe interpose`r` I 50. For the purpose of retaining the interposer in the desired non-interposirig position, the trigger |82 i's spring biased by means of spring 200 (Figures 10 and 11) into latching position.

The trigger |82 has a central mounting portion 20| which is perforated at 202. vAn integral projection of the material ofthe trigger 203 extends into the perforation 202 and terminates in a pointed angular portion 204 which provides a bearing for the trigger upon its shaft, permitting rotation thereof upon the shaft within predetermined limits. The mounting of the trigger,

as is seen in Figures 10, 11 and 14 comprises a spindle 2|0 preferably integrally formed from and secured to the wall of the housing and halvlng a notch 2|| therein.

The angular point 204 ofthe trigger projects into the notch 2|| which thus provides an angular bearing surface. 'Ihe trigger |82 may thus rotate within predetermined limits on the spindle 2|0. A sleeve 2|2 is mounted on the spindle 2|0 and between the side of the trigger and the side of the cover plate, thus accurately positioning the trigger upon the spindle. A hole in the spindle 2|0 at 2|3 (Figure 10) lpermits one end of the spring 200 to enter therethrough and engage a Wall of the groove or notch 2| I; the spring is wound about th sleeve, the other end at 2|6 engaging the trigger |82.

The spring is so arranged that it 'exertsa rotative force upon the trigger about the spindle 2|0 in a counter-clockwise direction with respect to Figure 9 and hence tends to bias the trigger I y ing portion |52 of the interposer from the latch 8 of the trigger. Accordingly, arms 220 and 22| are provided on the trigger to cooperate with elei 3l, the thermal element 34 and ments which respond .mechanically to variations in the amount of current.

Trigger release arm 2201s so arranged as to cooperate with the vmember `245 of the solenoid assembly 23|!- in the manner shown in Figures 4, 5, 3 and 9. As has beenab'ove noted, the solenoid is in the current path through the-movable and stationary contacts. Thus.- with respectto Figure 4, the current enters at the connecting lug or terminal 45, passes through the contact blocks and the members 33 and 3l into the solenoid and thence through the wire braid the lug 33 and bar 32 into the opposite terminal 30.

'I'he solenoid coil 31 isy composed of several turns of conducting materialwhich. in the pre,

the present invention. is

8 and 9 is mounted on an insulating sleeve 23| which prevents any current-leakage between the l successive turns oi' the lcoll and at the same time serves to insulate the coil from other members of the mechanism.

lThe insulating sleeve 23| may be secured withthe vhousing in any suitable manner. Thus be supported in a 1l of the housing in ene end thereof may at 232 depression of the bottom wa and the opposite end 'thereof in a U-shaped member 233 preferably integrally molded from a wall of the housing.

It will be noted that the contact engaging spring urges the contact member 40 towards the molded wall of the housing. The point of engagement of this spring withthe bar 39 is between the contact and the coil. The spring thus produces reactions at each end of the bar 38 to 39: one, producing contact engaging pressure when the interposeis are retracted; the other maintaining the solenoid assembly in the supporting members above mentioned.

For purposes of securing the support of the sleeve 23| at 232 in the housing, a steel core 234 having a ilange 235 engaging the sleeve may be secured at the bottom of the sleeve to provide a suitable bearing for the main armature spring and further to rigdify and strengthen the sleeve against any stresses that may be placed thereon. 'I'he movable solenoid armature '240 is slidably mounted in the top of the sleeve 23| and preferably may be maintained in the normal raised position shown in Figure 8 by the compression spring 24| which is placed between the base of the movable armature and the top of the stationary core. Since the slidable amature 240 is preferably made of steel or any other suitable magnetizable material, it may be drawn down so that it extends substantially within the coils 31 of thesolenoid when a suiiicient current is passed through such coils.

The end 232 of the coil having the flange member 235 may be inserted in the depression in the wall of the housing as seen in Figure 8, While the upper end of the sleeve is positioned in the U- shaped positioning element 233. The spring |00 the coils 31 of may be supported are passing through the even permit descent of the armature when only passing through of the interposer |50,

Coneqllently,

ers which control the position of the movable contact with respect to the stationary contact.

Spring 24| of the solenoid should be so calibrated and arranged that it will permit the drawing of the armature 24| within the coils of the solenoid Ain response only to an overload suiliciently excessive to possibly cause damage. That is, the spring 24| should not permit descent ot the solenoid rents customarily to be expected in the circuit coil 31. Nor should it slightly excessive currents are the coil. But the movement of the armature 24| into the coil should be in response only to exces- 1 sive loads.

The circular cross-section of the armature 24| and the free fit thereof within the sleeve 23| permits it to slide readily. A rectangular trigger arm engaging member 245 is secured either by welding or by any other suitable means to the top of the armature. Preferably as is seen in Figure 15, the trigger arm engaging member 245 is squared-oil and preferably the interior wall 245 (Figure 9) is close to the plate 245 of the armature (see also Figure 6).

As is therefore seen particularly in Figure 6, while the squaring-oft of the plate 245 does not interfere with the rise or fall of the armature, it prevents undue rotation of the armature to as to engage the trigger and to ensure that it will not rotate out of engagement with the trigger.

The slots 241- circuit or occasion any loss of energyv owing to A was originally biased by the trigger spring 200, causes a movement of the latch portion ISI thereof out of engagement with the bearing of the latch engaging arm |52 of the interposer |50 and thus removes any restraint upon the rotation thereby permitting the to drive the interposer in Figure 9, where the interposer |50 as will. now be clearly understood, extends between the movable and stationary contacts. l

Obviously, any such tripping ofthe interposer |50 into circuit opening position shown in Figure 9 will not occur owing to the energization of the solenoid 230 unless the movable and stationary contacts are pressed together, that is, unless the entire mechanism has first been placed in the position shown in Figure 5 where the manthe solenoid coil may rotate to pex'- mitthe movable contactcarrying armto rise or fallin response to the movement ot theinterpos armature 24| when ordinary cur-- (Figure 16) cut into the arma- I 8 l ually operated interposer 50 is no longer Vbetween them. i

As will be noted in Figure 5, when 4the manually operated interposer 50 is moved from the open circuit position of Figure 4 to the closed circuit position of Figure 5 then not only does itpermit the circuit to be closed between the' the movable and stationary contact-occursinmovable and stationary contactsbut also it isl 1' moved to 'a position where it will notinterfere with the descent of the automatically operated interposer upon release of its latch engaging arm |52. So'that when the automatically operated interposer |50 moves from the position shown in Figures 5 and 8 into the position shown in Figure 9, in responseto over current conditions, it is clearly free todo so without interfering with lthe interposer 5|i.

Obviously when the interposer |50 moves from the position shown in Figures 5 and8 to the position shown in Figure 9, it engages and raises the wheel and separates the stationary and movable contacts in exactly the same manner as has been shown heretofore inthe manually operated interposer 50. The manually operated interposer 50 isoif-set out of the principal plane of 'the main portion of the manual operating lever 23 so that it will 'be coplanar with the automatically operated interposer |50.

This condition simplifies the resetting process when the automatically operated interposer |50 is tripped.

Obviously once the automatically operated interposer |50 is tripped to separate the contacts,

deupendently of the manual operatedlever 23.

-'I'he spring 200 which biases the trigger `|82 `in the proper position shouldl preferablybe only of sufficient strength for this purpose. Otherwise it will benecessary not merely to calibrate the spring 24| of the solenoid in accordance withthe particular overload current conditions which are to be expected but also to calibrate the spring 200 in accordance therewith. 'A r It will also be possible, should it be desirable, merely to depend on thespring 200 of the trigger and to arrange this spring so that it'will permit a release of the latch only when a sufficient force is exerted upon the armature to rotate the trigger despite the force of the spring. In such latter case, spring 24| will not be necessaryi I have here shown, however, the preferred embodiment wherein compression spring 24| which may readily'be calibrated is utilized to resist the force exerted upon the armature by the DS'Sage of current through the solenoid. By this means,`

the automatically operated interposer |50 may be tripped in response to a specific excessive overload of substantial extent. It maybe necessary or desirable to effect a similar tripping operation of the interposer |50 when an overload which is not greatly excessive but is nevertheless continuous then the solenoid coil 31 is no longer energized v and the spring 24| is free to restore the armature 240 to the original position shown in Figure 8.

There is therefore no restraining force upon the trigger arm 220, and the spring 200 of the trigger |82 is then free to restore the trigger to its original position preparatory to latching engagement with the arm v|52 of the'interposer |50. Since theinterposer 50 and the interposer |50 are coplanar with respect to each other, it will be then clear that the movement-of the manual operating lever 23 from the clos'd circuit position shown in Figure 5 to the open circuit position shown in Figure 4 will result in a corresponding movement of the interposer 50 as shown and will also therefore result in the pushing up will be in latching engagement `with the latchr;

|8| of the trigger |82. And the circuit breaker will have been restored to its original non-tripped position but the circuit will then remainopen since in the very. operation of resetting the interposer |50, the interposer 50 has been moved into position between the contacts.

Subsequent to this operation which thus results in the position of the members shown in Figure 4, inorder to' restore the circuit, the manually operable interposer 50 must be moved back to the position shown in Figure 5. If, during such movement, and at the moment the movable contact touches the stationary contact, over current Vconditions still exist on the line, then the solenoid" coil 3'| will be immediately energized to trip the automatcally'interposable barrier |50 to tripped position.

In order to accomplish this purpose, I provide a which may occur in this circuit. The thermal bimetallic element 34 is so arranged that, the lower end thereof will be rotated clockwise with respect to Figure 8 under the inuence of heat. The current path from the connecting lug 45 through the contacts and to the connecting lug 30 is through the thermal element 34. Thus the current is led from connecting lug 45/throughv the bar 44 to the contact surfaces 42 and 4|, the contact supporting arms 39 and 38, the solenoid coil 31, ythe wire braid 36 to the thermal element; from the thermal element, the current flows into the thermal element supporting arm 33, thence through the bar 32 to the opposite connecting terminal 30.

Any overload conditions on the line which may result in the passage of suillcient current to generate heat in the circuit but which may not be of suiiicent intensity to energize the solenoid 230 may neverthelessI be sumcient to cause a bending of the thermal element 34. The thermal element 34 preferably is so calibrated that it will bend into engagement with the arm 22| 'of the trigger under predetermined. excessive load conditions which are not greatly in excess of the desired current Vcondition but which nevertheless result in the generation of excessive heat.

Upon the bending of the thermal element 34 in response to such heating conditions in the circuit, the end thereof will be swung over in the manner shown in the dotted lines of Figure 5 into mechan, ical contact with the trigger arm 22| and will cause' a rotation of the trigger |82 about the spndle 2 0, such rotation releasing the latch portion |8| thereof from the metallic bearing |00 of the latch engaging arm |52 of the automatically 'A interposable interposer |50.

lThis permits a tripping operation to occur and permits the compression spring |10 to force the automatically operated interposer |50 into the position shown in Figure 9.

'I'he automatically operated interposer may then be reset in the manner above described by the operation of the manual operating lever 23, but the trigger |02 will not be rotated to latching position by its spring 200 until the heating conditions which resulted in a curling of the thermal element'34 have been removed.

Thus, should the interposer |50 be reset in the manner above described immediately after tripping in response to heating conditions, it will immediately trip'once more owing to the fact that the thermal element will not have had an opportunity to cool off suiciently to permit it to disengage the trigger arm 22|. For this reason therefore, the interposer 50 cannot be reset until whatever heat has already been generated in the circuit has had an opportunity to radiate away. If, after such radiation has occurred, the interposable barrier |50 should be reset and an excessive overload occur, the solenoid operating mechanism 230 will cause another tripping; and should there be in the case of such resetting a slight overload resulting in the generation of heat once more, then after heat has been generated for a suilicient amount of time to permit the curling over of the thermal element 34, the interposer |50 will again be tripped and the circuit broken.

In every case it must be understood that the operation of the interposer l|50 is completely free of the manual operating arm 23 and that it is absolutely impossible to maintain the circuit in closed circuit position when fault conditions exist upon the line.

The circuit breaker may be adjusted for dferenttypes of excessive overloads by proper calibration, and interchanging of the spring 24|, and it may be adjusted for different responses to slight or heating overloads by either a change in the bi-metallic element or a shifting of the bi-metallic element 34 with respect to the trigger arm 22| so as to require a difference in the amount of bending of the thermal element before it is in mechanical contact with the trigger arm 22|.

In order to provide for such shifting of position I provide that a screw 210 be threaded through the arm 33 which supports the thermal element 34 and that the end of this screw bear against the ledge 21| in the interior of the housing. The arm 33 is made of resilient conductive material and is sufliciently elastic so that upon rotation of the screw 210 the arm 33 will be moved closer to or further away from the ledge 21| thus changing the position of the mounting of the thermal element 34 and shifting it closer to or further away from the trigger arm 23|.

The mounting portion 6| of the manual oper ating lever 23 is so arranged that whatever the position of the manual operating lever, Whether on or off, the slot 80 is completely covered over so that virtually no dust may enter from the outside into the mechanism.

This results, however, in making it either difficult or impossible to examine the interior of the mechanism while the circuit breaker is mounted upon the panel board to determine whether rthe circuit breaker has been tripped. As a matter o f fact, even though the nger grasping portion 60 of the manually operated lever 23 is in the closed l circuit position shown in Figure 5, the circuit breaker may be tripped open by the dropping of the interposer to the position shown in Figure 9 without changing the position of the linger grasping portion 60. Thus unless some outward visual indication is provided as to the position of the interposer |50, it will be diiiicult if not impossible to determine whether a circuit breaker has been tripped. f

Accordingly, I have provided a visual indicator which will readily show the position of the automatically operated interposer |50. The visual indicator is preferably a fiat metallic member 300 (Figures 5 and 16) carrying a flag 30| and having a perforation" 302 registerable with the mounti-ng shaft 12 and an angular projection 303 registerable with the angle 14 of the mounting shaft. The n indicator 300 is mounted upon the shaft 12 above the interposer |50 and the mounting portion 6| of the manually operated lever 23. 'I'he indicator disk 300 also has a linger 305 preferably at right angles to the main portion of the disk 300 and extending as is shown in Figure 9 immediately below the latch engaging arm |52 of the interposer |50.

A spring 306 (Figure 9) is at one end thereof engaged in an opening 301 of the automatically operated interposer |50 and at the other end at 308 is caught beneath the nger 305. The central coil portion thereof is wound about the shaft 12 and is placed between the automatic interposer |50 and the manual operating arm mounting 6|.

The spring 306 and especially the end 308 thereof is therefore biased to raise the finger 305 and thus is biased in such a direction as to cause a rotation of the disk 300 so as to raise the flag 30|. Normally, however, when the automatically operated interposer |50 is in the latched position shown in Figure 8, the latch engaging arm |52 thereof presses down the finger 305 against the bias of the end 308 of the spring and hence also presses down the flag 30| so that it is not visible. When the automatically operated interposer |50 is tripped into the position shown in Figure 9-and the latch engaging portion |52 thereof is raised, then the end 308 of the spring pushes up the finger 305 of the indicator and pushes the ag 30| up into the slot where it may be visible from the outside alongside the mounting portion 6| of the manual operating lever 23.

Accordingly, even though the finger grasping portion B0 of the manual operating lever 23 is in the apparent closed circuit position, the appearance of the ag 30| in the slot 80 alongside the mounting portion 6| of the manual operating lever will immediately give an indication that the circuit breaker has been tripped to open circuit position.

In order to provide a recess in the mounting portion 6| to permit the iiag 30| to appear in the slot 80, the mounting portion 6| is cut-out at 3|0 to a depth vsufficient to permit the entry of the flag 30| therein (3|0, Figure 5).

In order to prevent any possibility during the opening of the contacts of any arcing over between the movable contact block 40 and the bar 44, I prefer to provide insulating barriers 320 and 32| (Figure 5) which may be mounted in notch 322 of the ledge or boss 323 in the bottom wall of the housing and in notches 324 a-nd 325 of an end wall of the housing.

In order further to protect the members against arcing, I provide an upper shield 340 (see Figures 5 and 16) having a T-shaped opening 34| therein to permit the engagement of the contacts and the passage of the wheel therethrough. This protectionshield may be formed or stamped to shape, the shape being, of course, determined by the contour of the housing and obviously this shield 346 is spaced from the bottom shield |36 by a distance sufficient to permit the free passage of the insulating interposers between them.

From the foregoing description it will be seen that each of the members of the circuit breaker is supported within the housing in such a manner that they may readily be assembled in connection therewith. The housing itself is so formed and constructed as to provide supporting elements of various types, most of which having hereinbefore been described. Thus, for instance, the bar 22 which is an extension of the connecting lug 30 is securely mounted within the housing assembly by the screw 366 (Figures 4 and 5) which passes through a lug 36| of the bar 32 and into an integrally molded rectangular support 363 of the housing. The bar 32 is also securely positioned within the housing by being mounted between the rectangular abutment 363 and the angular portion 364 of the housing. i

Each of the interposers and the manual operating lever rotates about a single spindle which is integrally molded from or secured to one wall of the housing.

The member 44 which carries the lug 45 is also securely mounted within the housing, as is seen in Figure 9, by being mounted in a recess'or channel 366 thereof. The various portions of the housing cooperate with other elements to provide stops for certain of the movements and to provide mountings and securement in the manner hereinbefore described. When the cover plate 2| is secured in place by the rivets 22, then each of the members is securely fixed in its operative position, particularly as is seen by the cross-sectional view of Figure 6. Thus, the final securement of all of the members is obtained after most of the members have merely been slipped into place by the attachment of the cover member 2| and the passing of the rivets 22 through the elements and the housing.

Obviously, suitable on-off indication may be printed or written on the outside of the housing in cooperation with the manual operating lever 23 and particularly the finger grasping portion 66. If so desired the mounted portion 6I of the manual operating lever may be lettered with the legend off at 316 (Figure 4) and with the legend on at 31| (Figure 5). Furthermore the indentation 312 of the mounted portion 6| of the manual operating lever-23 may be provided and may be suitably colored to indicate the on position, since it will be visible only when the finger grasping portion of the manual operating lever 23 has been moved to the on position. Y

From the foregoing description of the various elements and the'manner in which they operate,

adaptability for panel l,board mounting in the manner shown inFigure 2.-

The lead connecting lug 36 as will be noted particularly with reference to Figure 4 is protected by the curved extension 396 of the housing and is enclosed between the cover plate and this extension. The lead 4s may, if desired, extend from the oppositeside or it may where necessary be protected in a similar manner by the extension 395 of the cover plate' (Figure 1) and/or by a corresponding extension of the housing. For ordinary panel board mounting where the lead 45 is to be used as part of the support for the circuit breaker upon the bus it may be desirable to use a cover plate which terminates at the side of the housing. For this purpose a weakening line 336 comprising indentations or grooves or any other suitable weakening elements may be provided in the cover 2| to facilitate the breaking off of the extension 335 so that the circuit breaker may readily be mounted in the panel board shown in Figure 2.

In Figures 2 and 3 a plurality of circuit breakers of the present invention are shown mounted upon a panel board with the leads 45 connected by suitable conductive securing means, as for instance, the screws 391, to a common bus 368, and the opposite leads connected to load wires 333 in any suitable manner. 'I'he leads 45 obviously maybe sumcient to provide adequate support for one end of the circuit breaker upon the common bus 336, although if desired any other securing means may be provided for this purpose, as for instance, the foot or lug 466 which may serve to engage a suitable clamp member upon the supporting base 46| of the panel or which may be extended and formed in such a manner as to provide a screw engaging means. As seen in Figure 3 flanged plate 466a may be screwed to the panel and may be formed to encase foot or 1u',r 466 to secure the same to the panel.

The foot 4.62 may be provided at the opposite end of the circuit breaker in order to provide the proper support for a screw 463 which may be passed there through into the panel board sup*- porting member 46| and secured in any suitable manner as for instance by the nut 464.

In order the insure that the circuit breaker will be perfectly level upon the panel board support 46|, the'foot 462 may be flush with the undersurface of the circuit breaker or, if this is not feasible, then an additional support 465 may be pro'- vided for the purpose. -The common bus may, if desired, be protected by any suitable circuit breaker. The circuitto any individual mechanism connected to anyone of the circuit breakers will thus be through the common bus 336 to the connecting lead 45 through the circuit breaker and the opposite lead 36 (Figure 4) and therefrom to theload wire 366 (Figure 3) to the mech.- anism, and then any suitable return, as for instance, to the terminal block 426 to which is connected the return wires from the individual loads; the terminal block 426 being connected to the side of the line opposite that to which the common bus is connected.

Each of the individual currents operated fromv each of the individual circuit breakers is thus fully protected by its own individual circuit breakers while the entire panel board and all of the elements operated therefrom may, if desired, be protected by a single circuit breaker .capable of handling the full load. The panel board itself, as is seen in Figures 2 and 3, comprises a main base or mounting portion 4|6 upon vwhich the panel board supporting member 46| is secured in any suitable manner. The main base and mounting portion 4|6 may have side members 4 and covering flanges 4| 2. The covering flanges H2 may be formed-in order to support .a slotted frame covering member 4.3 which will conceal all of the circuit breakers except for the top surfaces thereof at lll, IM from which the finger grasping portion il) of the manual operatinglever 23 projects.

In this manner no part of the circuit breakers or of the panel board or of the connecting wires are accessible except for the manual operating lever above mentioned and' except for the indicating means previously described. If desired, also a suitable cover may be mounted upon the flanges H2 to cover over theentire panel board against unauthorized operation thereof. Where the circuit breakers are thus to be mounted closely adjacent to each other,. the ends of rivet 22 may be'countersunk in the molding (and bosses placed thereabout) to provide an air space between said rivet ends so that they will not be in contact with similar rivet ends on adjacent breakers. The rivet ends on adjacent breakers (cf. Figure 3a), may then extend slightly into the counterbore. Such adjacent rivet ends are the ones extending from the cover plate. The cover plate is a die cut blank and the bend of the rivet engages the cover` plate at the rivet openings, while the opposite ends of the rivets in the counterbores or recesses of the molding are spun down. Where only a thermal trip is desired without changing the structure of the device, then the core of the solenoid coil may be removed or member 245 of the core may be removed, lthus leaving a dummy solenoid bushingaand coil; in such case, only the thermal trip will operate.

In this case also, the coll arrangement may be dispensed with, and the braid 36 from the thermal element may be connected to a metallic tube or other rivetable element which may carry the movable contact arm. Such tube or rivetable element may rotate about an insulating tube similar tothe insulating tube 23| of the solenoid.

The present circuit breakeri is comprised of a magnetic trip and a thermal time delay element may be incorporated in the usual form of power and light panel to handle branch circuits. The members as has been noted are readily mounted in any suitable support upon the panel and require no more space than a fused switch, and, taking into consideration the expense of replacement of fuses and the expense of operation of the fused switch, they are better than an adequate substitute therefor.

They are designed to be mounted in a panel with a number of units side by side with the line terminal of each circuitbreaker screwed directly to the common bus, this screw also serving to hold one end of the unit mechanically,

the opposite end of the circuit breaker being` mechanically supported in any suitable manner. In this manner therefore any individual units may be removed and replaced without disturbing adjoining units.

As has been above noted the circuit breaker of the presentinvention is trip free in that it will open even though the handle is `held in closed position and the switch cannot be held against overload or short circuit. The only way in which the circuit breaker may be reset after the interposer has been tripped is by moving the manually interposable interposer between conthe contacts will again cause the actuation of the thermal and/or solenoid elementsto cause tacts and thus maintaining the contacts in open circuit position. Should the circuit protected by the circuit breaker still be under overload conditions, then permitting the manually interposaele interposer to be moved away from between the automatic interposable interposer to move l aration therebetween.

The circuit breaker, as has been noted, trips immediately upon an excessive overload owing to the operation of solenoid means above described. f'vIhe thermal tripping means which acts in response to an overload which is not greatly excessive, but nevertheless isexcessive, is slowly heated as this minor overload continues until it eiects the tripping operation above described. As the overload increases the thermal element acts more and more rapidly. However, should excessive overloads occur, thenit may be dangerous to allow any delay until the thermal element is suiliciently heated to accomplish the tripping operation and accordinglythe solenoid tripping mechanism acts instantaneously upon greatly excessive overloads.

Furthermore, the ability of the present circuit breaker to trip at high speeds upon greatly excessive overloads would serve to prevent the between the contacts and thus the sepmain protecting circuit vbreakeri'rom tripping upon the occurrence of an excessive overload in a single branch circuit, and thus will serve to prevent the other branch circuits operating from the same bus from being disconnected from the main circuit.

In the foregoing description, cooperating elements have been set forth and the interrelation therebetween has been described.

Various modications and changes in the diierent parts will now be obvious to those skilled in the art. Accordingly, it is desired to be bound not by the specific disclosures herein but only by the appended claims.

This application is led simultaneously with the application of William M. Scott, Jr., Serial No. 332,037 for Circuit breaker, the application of Frank J. Pokorny, Serial No. 331,984, for Circuit breaker, and the application of Herbert C. Graves, Jr., Serial No. 331,982, for Circuit breaker. In this application I have claimed those inventions and portions of the structure in said same circuit and operating means for rotating said conductor and said entire solenoid coil about said axis to move said contacts into and out of engagement, said operating means being controlled in accordance with the degree of energization of the solenoid.

2. In a circuit interrupter, a support, a solenoid coil formed by a rigid conductor having a plurality of turns about an axis, an extension of said conductor substantially normal to said axis, a contact on said support for connection to an electrical circuit, a corresponding contact on said extension, means for connecting said solenoid in said same circuit and operating means for rotating said conductor about said axis to move said contacts into and out of engagement, said operating means being controlled in accordance with the degree of energization of the solenoid, v

3. In a circuit interrupter, a support, a solenoid coil formed'by a rigid conductor having a plurality of turns ,about an axis, ,an extension of said conductor substantially normal to said axis, a contact on said support for connection to an electrical circuit, a corresponding contact on said extension, mea'ns for connecting said solenoid in said same circuit and operating means for rotating said conductor about said axis to move said contacts into and out of engagement, said operating' means being controlled in accordance with the degree of energization of the solenoid, a spring member engaging said extension intermediate said solenoid coil and the contact on said extension for holding said solenoid .coil in place and biasing said contact toward closing position.

4. In a circuit interrupter, a support, a solenoid coil formed by a rigid conductor having a plurality of turns about an axis, an extension ofl said conductor substantially normal to said axis, a contact on said support for connection toan electrical circuit, a corresponding contact on said extension, means for connecting said solenoid in said same circuit and operating means for rotating said conductor about said axis to move said contacts into and out of engagement, said operating means being controlled in accordance with the degree of energization of the solenoid, a. fiat spring mounted on said support, a spring member engaging said extension intermediate said solenoid coil and the contact on said extension for holding said solenoid coil in place and biasing said contact toward closing position.

5. In a circuit interrupter, a support, a solenoid coil formed by a rigid conductor having a plurality of turns about-an axis, an extension of said conductor substantially normal to said axis, a

contact on said support for connection to an electrical circuit, a corresponding contact on said extension, means for connecting said solenoid in said same circuit and operating means for rotating said conductor about `said axis to move said contacts into and out of engagement, said operating means being controlled in accordance with the degree of` energization ofthe solenoid, a flat spring mounted on said support, a spring member engaging said extension intermediate said solenoid coil and the contact on said extension for holding said solenoid coil in place` and biasing said contact toward closing position, the portion of said spring engaging said exten-` sion having lateral positioning turing said extension.

6. In a circuit interrupter, a support, a soleelements capnoid coll formed by a rigid conductor having a plurality of turns about an axis, an extension of said conductor substantially normal to said axis, a contact on-said support for connection to an electrical circuit, a corresponding contact on said extension, means for connecting said solenoid in and means in said support for retaining said solenoid coil. t

7. In a circuit interruptena support, a solenoid coil formed by a rigid conductor having a plurality of turns about an axis, an extension of said conductor substantially normal to said Y axis, a'contact on said support for connection,v

to an electrical circuit, a corresponding contact on said extension, means `for connecting said. solenoid in said same circuit and omrating means for rotating said conductor about said axis to move said contacts into and out of engagement, said operating means being controlled in'accordancel with the degree of energization of the solenoid, and .a spring member engaging said extension for holdingA said solenoid coil in place, and pocket members in said support for retaining said solenoid coil. l l

8. In a circuit interrupter, a support, a solenoid coil formed by a rigid conductor having a plurality of turns about an axis, an extension of said conductor substantially normal to said axis, a contact on said support for -connection to an .electrical circuit, a corresponding contact on said extension, means for connecting said solenoid in said same circuit and operating means for rolbers in said support for retaining said solenoid coil, said members comprising a U-shaped member extending from saidsupport perpendicularly to the axis of said coil for circumerentially engaging a portion of said solenoid coil.

OTTO JENSEN. 

